Dental chair



t e e h S W e e h S 2 R WA w L A m vWE .D A m d 0 M O W Patented June 5, 1894.

INVENTOR WITNESSES (No Model.) 2 Sheets-Sheet 2.

- A. W. BROWNE.

DENTAL CHAIR.

N 520,948v Patented June 5, 1894.

INVENTOR WITNESSES against turning about the pedestal.

UNITED STATES PATENT OFFICE;

ARTHUR W. BROWNE, OF PRINOES BAY, NEYV YORK, ASSIGNOR TO THE S. S. WHITE DENTAL MANUFACTURING COMPANY, OF PHILADELPHIA,

PENNSYLVANIA.

DENTAL CHAIR.

I .SPEGIFIGATION forming part of Letters Patent No. 520,948, dated June 5, 1894.

Application filed February 5, 1894. Serial No. 499,052. (No model .i

To all whom it may concern.

Be it known that I, ARTHUR W. BROWNE, a citizen of the United States, residing at Princes Bay, in the county of Richmond and State of New York, have invented certain new and useful Improvements in Dental Chairs; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same. I

My invention relates to certain improvements, as hereinafter claimed, in means for supporting and vertically adjusting the bodies of dental chairs.

In the accompanying drawings which show a suitable embodiment of my improvements, Figure 1 is a view partly in side elevation and partly in vertical section, with some parts of the chair--illustration of which is not needed-omitted. Fig. 2 is a plan view with the chair body removed. Fig. 3 is a view on an enlarged scale partly in plan and partly n section on the line 3 of Fig. 1; and Fig. 4 1s a View also on an enlarged scale partly in plan and partly in section on the line 4 of Fig. 1.

A base or pedestal comprising the supporting legs A and cylindrical column or post A (see dotted lines Fig. 1) carries a hollow cylinder B which is adapted to turn horizontally about the pedestal. A clamp screw actuated by a lever B serves to lock the cylinder B Carried by and preferably formed with the cylinder is a curved hollow carrier 0 for two curved rack-barsDD which support the chairbody, as in turn to be explained. A side plate 0 of the carrier 0 constitutes a detachable and adjustable portion thereof bolted or screwed 1 in place. This carrier extends outwardly and downwardly from the cylinder and is supported by means of a roller a at its outer end upon the floor upon which the pedestal rests,

so that the carrier-may readily be turned about the pedestal with the cylinder.

The rack bars D D extend parallel with each other and are arranged side by side, arib d on one of the bars engaging with a groove in the other bar to insure that they'are maintained in proper relation to each other. A

clamp consisting of a screw actuated bya lever E serves to force inward the side plate of the carrier to firmly clamp the rack bars against lateral or vibratory movement in their carrier after adjustment of these bars. The

rack-bar D is slightly longer than the rack-- bar D. A pinion F engages with the rack bar D and a larger pinion F engages the teeth of the other rack-bar D. These pinions are secured toashaft G mounted to turn in bearings in the carrier 0 O and actuated by a crank G. At their upper ends the rack bars spread apart or incline away from each other and are jointed by means of pivots g g,

- one in advance of the other, to a chair body carrier H provided with journals or trunnions I Ito which the chair body 3 is pivoted so as to be capable of tilting vertically. A slot is provided in the chair body carrier for the pivot g to work in. A lever K secured to the chair body carrier H and acted upon by a spring 70, and a curved notched detent plate K secured to the chair body, constitute suitable means for locking the chair body in the position to which it may be adjusted by rock ing it about its carrier trunnions. A pawlZ is secured to a rockshaft mounted to turn in the carrier 0 C for the rack bars, and a lever secured to the rockshaft of the pawl provides for disengaging the pawl fromthe rack bar D with the teeth of which it is normally engaged to uphold the rack barsand the chair body supported thereby.

From the above description it will be understood that rotation of the pinions F F vertically adjusts the rack-bars which support the chair-body; and that undesirable tilting of the chair body as the rack-bars are moved up or down is prevented by causing the rack-bar D to move somewhat faster than the rack-bar D which is pivoted to the chair body carrier at a point in rear of the pivotal connection between this carrier and the other bar D. The difference in the size of the actuating pinions is such as to insure proper operationof the rack-bars to avoid tilting the chair body. The rack-bars are lowered by tripping the pawl which upholds them. At the same time the speed of descent of the rack-bars may be controlled by the crank attached to the pinion shaft. It will be seen that the chair-body is given a wide range of vertical adjustment.

Obviously, instead of projecting the carrier for the rack bars to the extent shown, it may be made shorter and the roller a dispensed with; and the rack bars when lowered may project beyond or in advance of their carrier when it is shortened; and instead of a slot being provided for the pivot g of the rack bar D, the pivot g of the rack bar D may work in a slot in the chair body carrier to provide for the diiterence in movement of the racks. My invention may be further modified in some respects while still retaining essential features of my improvements.

I claim as my invention 1. The combination of the curved rack bars extending parallel with each other and arranged side-by-side, the carrier in which the rack bars are vertically adjustable, means for supporting said carrier, the chair body, the chair body carrier to which the rack bars are jointed at their upper ends the one in advance of the other with the jointing pivot at the upper end of one of said bars having sliding connection with the chairbody carrier, and means for actuating the rack bars and for upholding them, substantially as set forth.

2. The combination of the two curved rack bars extending parallel with each other and 0 arranged side-by-side, the carrier in which the rack bars are vertically adjustable, the cylinder carrying said carrier, the pedestal supporting the cylinder and about which the cylinder may be turned, the chair body carrier to which the rack bars are jointed at their upper ends the one in advance of the other with the jointing pivot at the upper end of one of said bars having sliding connection with the chair body carrier, means for actuating the rack bars, and means for upholding them, substantially as set forth.

3. The combination of the curved rack bars, their carrier, the cylinder carrying said carrier, the pedestal supporting the cylinder and about which the cylinder may be turned, the chair body carrier to which the rack bars are jointed the one in advance of the other, the pinions of different sizes gearing one with each bar, means for actuating the pinions, and means for upholding the rack bars, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

ARTHUR W. BROWNE.

Witnesses;

ELI I. STARR, E. EUGENE STARR. 

